The long term goal of this work is to accurately measure spinal cord perfusion in humans and to use this knowledge to improve the management and clinical outcome of patients with diseases in spinal cord. The Specific Aims for this project are: 1) To develop the VASO MRI technique for quantitative measurement of scBV in humans and to test the validity of the measurements;2) To measure scBV in thoracic and lumbar regions and to compare the gray and white matter scBV values in different segments;3) To use the VASO MRI technique to test whether or not scBV values in acute spinal cord injury (SCI) patients are abnormal. Spinal cord hemodynamics is a key component in the pathophysiology of many related diseases, such as spinal cord trauma, ischemia, infarction, spinal arteriovenous malformation (AVM), and spinal tumor. Therefore, an accurate evaluation of the spinal cord perfusion and hemodynamics will benefit the diagnosis and treatment of the patients, and will also improve our understanding of the disease pathophysiology. While the perfusion measurement techniques for brain have been the focus of many investigations, the methodologies for spinal cord perfusion are relatively not well developed. For human studies, the research on spinal cord perfusion is virtually non-existing due to a lack of techniques to quantify the perfusion parameters. The purpose of this work is to develop a quantitative method to measure spinal cord blood volume (scBV) using magnetic resonance imaging (MRI). This technique uses pre- and post-contrast VASO images and is based on the T1-shortening effect of the Gd-DTPA (gadolinium complex of diethylenetriamine pentaacetic acid) contrast agent. A unique advantage of this technique is that the quantification of scBV does not require the knowledge of the arterial input function, allowing accurate estimation of absolute BV values in physiological units (ml blood per 100ml tissue). Cervical, thoracic and lumbar scBV will be measured at high spatial resolution to allow for distinction of gray/white matter and segment-specific scBV values will be calculated. ScBV values in patients with SCI will be quantified and correlated with their functional recovery. PUBLIC HEALTH RELEVANCE This project will develop a technique that will allow physicians to evaluate the blood supply to the spinal cord. Being able to measure blood supply will help physicians with the diagnosis and treatment of several spinal cord diseases, including spinal cord injury, spinal cord ischemia, and spinal tumor.